Should you ever meet Donny McCaslin, you’ll encounter an imposingly tall fellow who’s one of the nicest guys you’ll shake hands with — and who wields a sax like few others. His band has gone electro-funk with fuzz-dub bass, analog synths and hard grooves. One of his newer tunes is called “Stadium Jazz,” which is a little tongue-in-cheek and with a little bit of the grand vision implied. They played a side stage in the morning. The audience didn’t know what hit ‘em.